This study reports a gallium-based thermal interface material (GBTIM) consisting of gallium oxides dispersed uniformly into the 99 % gallium metal. The wettability of GBTIM with other materials is ...disclosed and compared. The thermal conductivity of GBTIM measured by a computer-controlled Mathis TCi thermal analyzer is ∼13.07 W m
−1
K
−1
at room temperature, which is significantly higher than that of conventional thermal greases. An experimental facility is described to measure the thermal resistance across the GBTIM under steady-state conditions and the thermal interface resistance is measured as low as 2.6 mm
2
kW
−1
with a pressure of 0.05 MPa, which is an order lower than that of the best commercialized thermal greases. Further, the GBTIM is formed into a desired shape to enhance thermal transfer, such as semi-liquid paste or thermal pad, which can be cut into a required shape.
A direct electronics printing technique through atomized spraying for patterning room-temperature liquid metal droplets on desired substrate surfaces is proposed and experimentally demonstrated for ...the first time. This method is highly flexible and capable of fabricating electronic components on various target objects, with either flat or rough surfaces, made of different materials, or having different orientations from 2D to 3D geometrical configurations. With a pre-designed mask, the liquid metal ink can be directly deposited on the substrate to form various specific patterns which lead to the rapid prototyping of electronic devices. Further, extended printing strategies were also suggested to illustrate the adaptability of the method. For example, it can be used for making transparent conductive film with an optical transmittance of 47 % and a sheet resistance of 5.167Ω/□ due to natural porous structure. Different from the former direct writing technology where large surface tension and poor adhesion between the liquid metal and the substrate often impede the flexible printing process, the liquid metal here no longer needs to be pre-oxidized to guarantee its applicability on target substrates. One critical mechanism was that the atomized liquid metal microdroplets can be quickly oxidized in the air due to its large specific surface area, resulting in a significant increase of the adhesion capacity and thus firm deposition of the ink to the substrate. This study paved a generalized way for pervasively and directly printing electronics on various substrates which are expected to be significant in a wide spectrum of electrical engineering areas.
Conventional approaches of making a flexible circuit are generally complex, environment unfriendly, time and energy consuming, and thus expensive. Here, we describe for the first time the method of ...using high-performance GaIn(10)-based electrical ink, a significantly neglected room temperature liquid metal, as both electrical conductors and interconnects, for directly writing flexible electronics via a rather easy going and cost effective way.
The new generation electric ink was made and its wettability with various materials was modified to be easily written on a group of either soft or rigid substrates such as epoxy resin board, glass, plastic, silica gel, paper, cotton, textiles, cloth and fiber etc. Conceptual experiments were performed to demonstrate and evaluate the capability of directly writing the electrical circuits via the invented metal ink. Mechanisms involved were interpreted through a series of fundamental measurements.
The electrical resistivity of the fluid like GaIn(10)-based material was measured as 34.5 µΩ·cm at 297 K by four point probe method and increased with addition of the oxygen quantity, which indicates it as an excellent metal ink. The conductive line can be written with features that are approximately 10 µm thick. Several functional devices such as a light emitting diode (LED) array showing designed lighting patterns and electrical fan were made to work by directly writing the liquid metal on the specific flexible substrates. And satisfactory performances were obtained.
The present method opens the way to directly and quickly writing flexible electronics which can be as simple as signing a name or drawing a picture on the paper. The unique merit of the GaIn(10)-based liquid metal ink lies in its low melting temperature, well controlled wettability, high electrical conductivity and good biocompability. The new electronics writing strategy and basic principle has generalized purpose and can be extended to more industrial areas, even daily life.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Against the backdrop of developing new arts, it is urgent for undergraduate colleges engaged in applied studies to change the traditional teaching model and adopt virtual simulation technology to ...build an experiment teaching system for the studies of traditional Chinese culture, particularly the Chinese tea ceremony. In this paper, a multi-level experiment teaching system is developed based on experienceknowledge-skills with multiple objectives, covering two physical sections and four functional modules, featured by immersive and interactive teaching methods. It encourages learning based on independent inquiry, enabling students to be flexible for innovation. It effectively integrates good teaching resources to serve multiple disciplines, ultimately achieving the goal of enhancing competency, elevating spiritual pursuit, and raising awareness of innovation.
Purpose. To explore the effect of VEGF (vascular endothelial growth factor) on the vasculogenic mimicry (VM) formation of Choroidal Melanoma (CM) through PI3k signal pathway, to find novel targets ...for CM therapy. Methods. This research investigated the molecular mechanism of VEGF promoting VM formation of CM. First, we evaluated the expressions of VEGF in 20 CM specimens by immunohistochemical determination. Then we detected expressions of VEGF, AKT, MT1-MMP, MMP2, and MMP9 of OCM-1 in hypoxia. siRNA was used to inhibit the expression of VEGF, to realize the control of the VM formation. The VM formation was evaluated through wound healing assay, transwell assay, and apoptosis. And then we testify the correlation of the VM and the factors in protein and mRNA level preliminarily. Results. VEGF protein was expressed in CM in all 20 cases of CM, especially along the VM. In hypoxia, the expression of VEGF in OCM-1 increased significantly. VEGF gene deletion reduced the proliferation, migration, and invasion of OCM-1. VEGF gene deletion impaired the expression of invasive associated genes like VEGF, p-AKT, AKT, MT1-MMP, MMP2, and MMP9. These results indicate that VEGF induce VM formation in CM by activating PI3K/AKT signaling pathway. Conclusions. VEGF promoted VM formation by the PI3K signal transduction pathway, indicating a molecular mechanism which may be used to develop new therapeutic targets for the clinical treatment of CM.
In this study, Ni nanoparticles were loaded into the partially oxidized gallium and its alloys to fabricate desired magnetic nanofluid. It was disclosed that the Ni nanoparticles sharply increased ...the freezing temperature and latent heat of the obtained magnetic nano liquid metal fluid, while the melting process was less affected. For the gallium sample added with 10vol% coated Ni particles, a hysteresis loop was observed and the magnetization intensity decreased with the increase of the temperature. The slope for the magnetization-temperature curve within 10–30K was about 20 times of that from 40K to 400K. Further, the dynamic impact experiments of striking magnetic liquid metal droplets on the magnet revealed that the regurgitating of the leading edge of the liquid disk and the subsequent wave that often occurred in the gallium-indium droplets would disappear for the magnetic fluids case due to attraction force of the magnet.
High speed videos for the impact of striking GaIn24.5 based magnetic liquid metal droplets on a magnet plate. Display omitted
•A feasible way to fabricate magnetic nano liquid metal fluid was presented.•Ni nanoparticles sharply increased freezing temperature and latent heat of magnetic nanofluid.•A hysteresis loop phenomenon was observed for the magnetic nanofluid.•Temperature dependent magnetization spanning from 10K to 400K was measured.•Impact phenomena of striking magnetic droplets on magnet were disclosed.
The current strategies for making electronic devices are generally time, water, material and energy consuming. Here, the direct writing of composite functional circuits through comprehensive use of ...GaIn10-based liquid metal inks and matching material is proposed and investigated, which is a rather easy going and cost effective electronics fabrication way compared with the conventional approaches.
Owing to its excellent adhesion and electrical properties, the liquid metal ink was demonstrated as a generalist in directly making various basic electronic components such as planar resistor, inductor and capacitor or their combination and thus composing circuits with expected electrical functions. For a precise control of the geometric sizes of the writing, a mask with a designed pattern was employed and demonstrated. Mechanisms for justifying the chemical components of the inks and the magnitudes of the target electronic elements so as to compose various practical circuits were disclosed.
Fundamental tests on the electrical components including capacitor and inductor directly written on paper with working time up to 48 h and elevated temperature demonstrated their good stability and potential widespread adaptability especially when used in some high frequency circuits. As the first proof-of-concept experiment, a typical functional oscillating circuit including an integrated chip of 74HC04 with a supply voltage of 5 V, a capacitor of 10 nF and two resistors of 5 kΩ and 1 kΩ respectively was directly composed on paper through integrating specific electrical elements together, which presented an oscillation frequency of 8.8 kHz.
The present method significantly extends the roles of the metal ink in recent works serving as only a single electrical conductor or interconnecting wires. It opens the way for directly writing out complex functional circuits or devices on different substrates. Such circuit composition strategy has generalized purpose and can be extended to more areas, even daily pervasive electronics.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Purpose
This meta-analysis was conducted to evaluate the efficacy and safety of single-dose dexamethasone implantation for treating persistent DME (diabetic macular edema) refractory to anti-VEGF ...(anti-vascular endothelial growth factor) drugs over a period of 6 months.
Methods
All related clinical trials were reviewed by searching electronic databases of PubMed, Medline, Web of Science, Cochrane Library, and EMBASE. The primary outcome parameters were best-corrected visual acuity (BCVA) and central macular thickness (CMT). We performed this meta-analysis by using Stata15.0.
Results
Ten clinical trials involving 362 eyes from 328 patients were eligible in the final analysis. After single-dose dexamethasone implantation, there was a significant improvement in BCVA from baseline to 1, 3, and 6 months with an average increase of − 0.15 logMAR (
p
< 0.001), − 0.14 logMAR (
p
< 0.001), and − 0.07 logMAR (
p
= 0.004), respectively. Further, mean CMT decreased significantly with an average reduction of 249.18 μm (
p
< 0.001), 217.66 μm (
p
< 0.001), and 91.56 μm (
p
< 0.001) at months 1, 3, and 6, respectively.
Conclusions
Our results indicate that switching to a dexamethasone implant could achieve significant anatomical and functional improvement among patients with refractory DME. Clinicians should be aware of this treatment option in refractory DME.
The structure, internal friction (IF) behavior, resistivity and magnetostriction property of Fe-18Ga alloy were systematically analyzed in this investigation. In the IF spectra of Fe-18Ga alloy ...covered from room temperature (RT) to 800 °C, a prominent IF peak (labeled as Ptr peak) was observed in the high temperature range 530 °C–690 °C besides the reported IF peak related with grain boundary relaxation in the moderate temperature range 400 °C–530 °C. The peak position of Ptr peak hardly changes with measuring frequency, implying that its mechanism is most possibly related with phase transition. Considering from the wide peak shape, Ptr peak can be decomposed into two components: the lower temperature Ptr1 peak located around 530 °C–605 °C and the higher temperature Ptr2 peak located around 605 °C–690 °C. Combined with calculated phase diagram, resistivity and magnetostriction analysis, the mechanism of Ptr peak was suggested to originate from the order-disorder phase transition related with Ga atom distribution in Fe-18Ga alloy: Ptr1 peak was ascribed to D03→B2 transition and Ptr2 peak was ascribed to B2→A2 transition, respectively.
Display omitted
•A prominent IF peak was observed in the temperature range 530 °C–690 °C in Fe-18Ga alloy.•The peak height of Ptr peak is closely related to the content of D03 phase.•Schematic diagram of Ptr peak is established based on two-phase model.•The mechanism of Ptr peak is ascribed to D03.→B2 and B2→A2 phase transition.
Purpose:
To assess the functional and anatomical consequences of single-dose dexamethasone (DEX) implants for the treatment of refractory macular edema (ME) secondary to retinal vein occlusion (RVO) ...after anti-vascular endothelial growth factor agents.
Methods:
A literature search of studies on switching therapy to DEX implants from anti-VEGF agents in refractory RVO patients was performed with five electronic databases (PubMed, Embase, Web of Science, MEDLINE, and Cochrane Library) prior to January 2022. The main outcomes included best-corrected visual acuity (BCVA) and central macular thickness (CMT) changes at different follow-up endpoints from baseline. All analyses were performed using Stata version 15.0.
Results:
The final analysis included four eligible studies with a total of 99 patients. After single-dose DEX implant application, BCVA improved significantly at 2, 3, and 6 months with an average gain of −0.23 logarithm of the minimum angle of resolution (logMAR) (
p
= 0.004), −0.20 logMAR (
p
= 0.027), and -0.09 logMAR (
p
= 0.021), respectively. Mean CMT reduction was also significant from baseline to 2 months (-241.89 μm,
p
< 0.001), 3 months (−222.61 μm,
p
< 0.001), and 6 months (−90.49 μm,
p
< 0.001). No serious adverse events were observed in any of the included studies.
Conclusion:
This meta-analysis showed that RVO patients with refractory ME could benefit significantly from switching therapy to DEX implantation, with efficacy lasting 6 months after a single-dose application. Intravitreal DEX implantation is a safe and effective option for refractory cases.
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